1. Field of the Invention
The present invention relates to a hand-held power tool which includes a shiftable transmission for driving a drive shaft, which is situated in a gear housing and is shiftable at least between a first gear and a second gear via a shifting member.
2. Description of the Related Art
These types of hand-held power tools are known from the related art, and include a shiftable transmission for driving a drive shaft, the transmission being designed in the manner of a reduction gear unit, via which a predefined motor speed may be reduced to a speed range of the drive shaft which is necessary for a particular application. For example, in cordless screwdrivers, cordless screw drills, and/or cordless percussion drills, motor speeds of approximately 20,000 rpm are reduced to a speed range of approximately 150 rpm to 2,000 rpm.
The reduction gear units are designed, for example, as multistage planetary gears which include at least two gears, so that a user of this type of hand-held power tool may shift it between a first gear and a second gear, for example, the first gear being a comparatively slow gear having high torque, and the second gear being a comparatively fast gear having low torque. For implementing the gears, such a planetary gear customarily includes three planetary stages; for shifting gears, in each case at least one of the three stages is deactivatable via a shifting annulus gear which is displaceable via a manually actuatable actuating element. A spring wire which is actuatable via an associated sliding element and connected to the displaceable shifting annulus gear is used as the actuating element. This spring wire may either be pivoted via a fixed point or shifted linearly.
A disadvantage of the related art is that a sliding element is comparatively difficult to operate, in particular when a user in question is wearing work gloves, which therefore makes handling inconvenient. In addition, when the sliding element is improperly or insufficiently moved, the shifting annulus gear may be moved into an intermediate position, which during operation of the hand-held power tool may result in damage to the planetary gear.